from Tkinter import *
master = Tk()

xmax=600
ymax=600
w = Canvas(master, width=xmax, height=ymax)
w.pack()

bounds = 3.
a=- bounds
b=  bounds
c=- bounds
d=  bounds
dx=(b-a)/xmax
dy=(d-c)/ymax


def f(x,y):
 return x**3 + y**3 - 2*x*y**2 - y*x**2 + 1

for i in range(xmax):
 for j in range(ymax):
  x=a+i*dx
  y=c+j*dy
  color="green"
  if f(x,y)<0:
    color="red"
  w.create_rectangle(i, ymax-j, i+1, ymax-j-1, fill=color, width=0)


mainloop()